Re: multicast replicator/outgoing links from node

[Yuri Pryadkin <yuri@who.isi.edu>]

Hi, Lori,

Lori Flynn  <lori@cse.ucsc.edu> writes:

> Hi all,
> 
> I want to find out if the neighbor (N1) of a node (N2) is considered by N2
> to be on an outgoing link for a specific multicast group (G).  
> 
> I'd like to access the outgoing interface list from within the multicast
> replicator of N2 (for group G), and then check to see if N1 is on that
> list.  
> 
> My question is:
> I can use the 'getRepByGroup' command to get the replicator, but how do I
> retrieve the outgoing interface list from this replicator? 

You probably can use 'slots' command on each replicator to get a list
of oifs.  Then you'll need to check if '[$ns link $n2 $n2] head' i.e. the
head of the link from n2 to n1 is on that list. 

> 
> 
> Additionally:
> Is Classifier/Multicast/Replicator or  Classifier/Replicator/Demuxer what
> I am working with?  (I am using a Pim DM spinoff protocol.)

Classifier/Multicast/Replicator classifies packets by (source, group,
iif).  Depending on these values, it sends a packet to one or another
Classifier/Replicator/Demuxer, whose job is to replicate packets and
pass them on to oifs.

> 
> Any help is appreciated!
> -Lori
> 
> ps. Reason I'm not using existing functions:
> If I used a standard multicast protocol, I would just use the functions
> 'RPF-link' and 'RPF-interface'.  However, the protocol I use is not
> standard, and the above functions don't work.  (Reason is that the above
> functions check to see if N1 considers/is qualified by N2 to be a parent,
> rather than if N2 considers N1 to be a child.)

You must be using an older version of ns.  I believe RPF-... functions
are not present in the current version.


  -Yuri